Although chafing-the rubbing of a body on the sea floor-is a common response of sharks to the attachment of irritating sharksuckers (Echeneis spp.), this behavior has not yet been analyzed in detail. I focused on the different forms and functions of chafing, with special emphasis on the use of sand ripples by sharks during chafing. A significant number of the 146 videotaped Caribbean reef sharks, Carcharhinus perezi (Poey, 1876), and blacktip sharks, Carcharhinus limbatus (Muller and Henle, 1839), preferred to chafe against sand ripples with either a parallel or perpendicular swim direction rather than a transverse swim direction. Tailbeat frequencies of the different forms of the chafing behavior were significantly larger than cruising frequencies. Results indicate that successful chafing requires that sharks employ pattern-recognition and body awareness during chafing